William pountney



(No Model.) I

-' 'W POUNTNEY.

GLASS LAMP GHIMNEY.

Patented- DecIll, 18 8 3.

- UNITED STATES PATENT OFFICE.

WILLIAM POUNTNEY, on ronr JnnvIs, NEW YORK.

GLASS LAMP-CHIMNEY.

SPECIFICATION forming part of Letters Patent No. 289,932, dated December 11, 188?,

Application filed April 10, 1883. (No model.)

To all whom it may concern:

Be it known that I, WVILLIAM POUNTNEY, of Port Jervis, in the county of Orange and State of New York, have invented a new and useful Improvement in Glass Lamp-Chimneys, of which the followingis aspeciflcation, reference being had to theaccompanying drawings, forming part of the same, in which Figures 1 and 2 are side views of a lampchimney that contains my invention; and Fig. 3 is a longitudinal section of the same on line wx,Fig. 1.

My invention relates to a glass lamp-chimney designed to be used on a lamp having a flat or bats-wing burner, and that is'peculiarly liable to be broken by the heat by reason of the unequal heating resulting from the edges of the broad flame coming in contact with the chimney or more nearly so than in the Argand or round-wick lamp; 'and the object of my invention is to provide a chimney to be used with a bats-wing burner that will endure unequal heating with less liability tobreakage than the common chimney. This object I attain by forming in the part of the bodyof the chimney which will be opposite the edges of the flames of the lamp when in use corrugations, as represented in the drawings, which I have found by trial will permit the glass to expand and contract without breaking more suddenly and. ate greater extent than without such corrugations, while the flat side of the chimney,being plane,transmits the light without divergence.

The chimney has the usual flat or oval form used with bats-wing or broad-flame burners. In this chimney I form corrugations upon the ends of the oval, which when thechimney is in use, are opposite and exposed to the extended edges of the flame of the lamp. The corrugations are made, as shown at a a.that is to say, neither longitudinal nor exactly circumferential, but, instead, diverging either way from the ends of the long diameter of oval or ellipse downward or upward toward the end of the chimney, preferably both ways, as

shown in Figs. 1 and 2. The corrugations may be one-fourth of an inch in width and an eighth of an inch (more or less) in depth. In

length they should extend around the ends of the ellipse. The corrugations may be formedin the blowing of the glass, the mold being suitably constructed for the purpose.

Oorrugations formed, as described, only on the ends of the oval in this class of chimneys form a very efficient protection against breakage by the varying action of the heat of the flame of the lamp, while they leave the entire sides of the oval flat and plane, or nearly so, for the direct transmission of the rays of light.

What I claim as my invention, and desire to secure by Letters Patent, is. v V

An oval glass lamp-chimney provided with the corrugations a con the ends of the oval, as and for the purpose described.

' W. POUNTNEY. In presence of- A. G. N. VERMILYA,

A. S. FITCH. 

